Tracing the fault that trips an RCD is not straight forward. The fault may appear to be on the kitchen circuit if that is the only circuit energised when the RCD trips. An RCD can be tripped by a fault on a circuit whose MCB is switched OFF.
One clue is that the RCD trips when a large load in is switched on.
A thorough test of ALL circuits on the RCD is needed with specific attention to insulation testing for Neutral to Earth faults. As testing for Neutral to Earth faults requires removal of wires inside the consumer unit some "electricians" are reluctant to do this testing properly and thus never identify the cause of the fault.
One clue is that the RCD trips when a large load in is switched on.
A thorough test of ALL circuits on the RCD is needed with specific attention to insulation testing for Neutral to Earth faults. As testing for Neutral to Earth faults requires removal of wires inside the consumer unit some "electricians" are reluctant to do this testing properly and thus never identify the cause of the fault.
